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PubMed | National Bureau of Investigation Forensic Laboratory, University of Helsinki, Vita Laboratory, LADR GmbH Medizinisches Versorgungszentrum and 2 more.
Type: | Journal: Forensic science international | Year: 2014

Hand-held electronic breath-alcohol analyzers are widely used by police authorities in their efforts to detect drunken drivers and to improve road-traffic safety. Over a three month period, the results of roadside breath-alcohol tests of drivers apprehended in Finland were compared with venous blood alcohol concentration (BAC). The mean (median) time between sampling blood and breath was 0.71h (0.58h) with a range from 0 to 6h. Some hand-held instruments gave results as the concentration of alcohol in breath and were converted into BAC assuming a blood-breath alcohol ratio (BBR) of 2260. The mean venous BAC (1.82g/kg) in traffic offenders was higher than the result predicted by the hand-held breath analyzers (1.72g/kg). In 1875 roadside tests, the relationship between venous BAC (x) and BrAC (y) was defined by the regression equation y=0.18+0.85x. The coefficients show both a constant bias (y-intercept 0.18g/kg) and a proportional bias (slope=0.85). The residual standard deviation (SD), an indicator of random variation, was 0.40g/kg. After BAC results were corrected for the time elapsed between sampling blood and breath, the y-intercept decreased to 0.10g/kg and 0.004g/kg, respectively, when low (0.1g/kg/h) and high (0.25g/kg/h) rates of alcohol elimination were used. The proportional bias of 0.85 shows that the breath-alcohol test result reads lower than the actual BAC by 15% on average. This suggests that the BBR of 2260 used for calibration should be increased by about 15% to give closer agreement between BAC and BrAC. Because of the large random variation (SD0.40g/kg), there is considerable uncertainty if and when results from the roadside screening test are used to estimate venous BAC. The roadside breath-alcohol screening instruments worked well for the purpose of selecting drivers above the statutory limit of 0.50g/kg.


Blomstedt P.,Åbo Akademi University | Blomstedt P.,University of Helsinki | Gauriot R.,University of Helsinki | Gauriot R.,Queensland University of Technology | And 4 more authors.
Journal of Chemometrics | Year: 2014

Statistical comparison of oil samples is an integral part of oil spill identification, which deals with the process of linking an oil spill with its source of origin. In current practice, a frequentist hypothesis test is often used to evaluate evidence in support of a match between a spill and a source sample. As frequentist tests are only able to evaluate evidence against a hypothesis but not in support of it, we argue that this leads to unsound statistical reasoning. Moreover, currently only verbal conclusions on a very coarse scale can be made about the match between two samples, whereas a finer quantitative assessment would often be preferred. To address these issues, we propose a Bayesian predictive approach for evaluating the similarity between the chemical compositions of two oil samples. We derive the underlying statistical model from some basic assumptions on modeling assays in analytical chemistry, and to further facilitate and improve numerical evaluations, we develop analytical expressions for the key elements of Bayesian inference for this model. The approach is illustrated with both simulated and real data and is shown to have appealing properties in comparison with both standard frequentist and Bayesian approaches. © 2013 John Wiley & Sons, Ltd.


Kriikku P.,University of Helsinki | Kriikku P.,Vita Health Care Services Ltd | Rintatalo J.,National Bureau of Investigation Forensic Laboratory | Pihlainen K.,Finnish Medicines Agency | And 2 more authors.
International Journal of Legal Medicine | Year: 2015

In this study, we sought to determine what impact the banning of 3, 4- methylenedioxypyrovalerone (MDPV) had on the incidence of MDPV-positive findings and on user profiles in driving under the influence of drugs (DUID) and postmortem (PM) investigations in Finland. All MDPV-positive cases and a selection of corresponding court cases between 2009 and 2012 were examined. The median serum concentration of MDPV in DUID cases was 0.030 mg/L and in PM blood 0.12 mg/L. The number of MDPV-positive cases decreased both in DUID and PM investigations after the drug was banned. The decrease in the mean monthly numbers of MDPV-positive DUID cases was 51.1%. In court cases, MDPV was rarely mentioned until banned and frequently mentioned thereafter. Of the convicted, 37% were without a fixed abode, 98% had other charges besides that of DUID, and 13% appeared in the study material more than once. In MDPV-positive PM cases, the proportion of suicides was very high (24%). Research on new psychoactive substances is required not only to support banning decisions but more importantly to be able to provide a scientific assessment of the risks of these new substances to the public and potential users. © 2015, Springer-Verlag Berlin Heidelberg.


Kriikku P.,Vita Health Care Services Ltd | Kriikku P.,University of Helsinki | Wilhelm L.,LADR GmbH MVZ Dr. Kramer and Colleagues | Rintatalo J.,National Bureau of Investigation Forensic Laboratory | And 4 more authors.
Forensic Science International | Year: 2013

The aim of this study was to assess the incidence of the use of desoxypipradrol (2-DPMP) among drivers apprehended on suspicion of driving under the influence of drugs (DUID) and the prevalence of the drug in post-mortem cases in Finland. Serum samples from drivers apprehended on suspicion of DUID and blood samples from post-mortem cases in Finland between October 2010 and May 2012 were analysed for the presence of desoxypipradrol. All samples were analysed for desoxypipradrol by mass spectrometric methods following comprehensive drug screening. Psychomotor performance of subjects was assessed by a clinician. There were 106 positive desoxypipradrol samples from apprehended drivers (1.7% of all confirmed DUID cases) in the study period. In most cases amphetamine and/or benzodiazepines were also present. The median (range) desoxypipradrol concentration was 0.073. mg/L (0.006-0.890. mg/L). The presence of other psychoactive drugs confounded assessment of the effect of desoxypipradrol on psychomotor performance except for one case in which it was the only drug present at pharmacologically active levels. Desoxypipradrol was found in 5 autopsy cases (0.05% of the investigated cases) and thought to contribute to death in two of these. Even though there are few data available on the pharmacology of desoxypipradrol, based on our findings, and the growing number of users, it is reasonable to assume that desoxypipradrol - a long-acting psychostimulant with dangerous side effects has an increasing detrimental impact on traffic safety in Finland. However, it was only rarely found to be the cause of death in post-mortem cases. © 2013 Elsevier Ireland Ltd.


Kriikku P.,Vita Health Care Services Ltd | Wilhelm L.,LADR GmbH MVZ Dr. Kramer and Kollegen | Rintatalo J.,National Bureau of Investigation Forensic Laboratory | Hurme J.,Vita Health Care Services Ltd | And 3 more authors.
Forensic Science International | Year: 2012

Phenazepam is a long-acting benzodiazepine that, unlike other benzodiazepines, is currently not scheduled as a narcotic in Finland, most other European countries or the USA. It is used as an anxiolytic, sedative-hypnotic and anti-epileptic, mainly in Russia. In Finland, as well as in some other countries, an increase in the unauthorized use of phenazepam has been observed in recent years.In the one year period between July 1, 2010 and June 30, 2011 the prevalence of phenazepam in Finland was assessed among drivers apprehended for driving under the influence of drugs (DUID), in medico-legal autopsy cases and in police confiscations of illicit drugs.In DUID cases an LC-MS/MS method preceded by solid phase extraction was used for the determination of phenazepam. In the post-mortem investigations the sample preparation consisted of liquid-liquid extraction followed by derivatization and the determination was carried out by GC-MS. The police confiscations were analysed by GC-MS.There were 141 positive phenazepam cases among apprehended drivers, representing approximately 3.5% of all confirmed drug cases (. n=. 4007) in this time period. The median (range) phenazepam blood concentration in DUID cases was 0.061. mg/L (0.004-3.600. mg/L). The median phenazepam concentration in cases with no concomitant stimulant use was significantly higher than the overall median concentration. Phenazepam was found in 17 medico-legal autopsy cases and the median (range) blood concentration was 0.048. mg/L (0.007-1.600. mg/L). Phenazepam was not considered by the medico-legal team to be the sole cause of death in any of the cases, the majority of them being accidental opiod overdoses. There were 26 seizures of phenazepam by the Police in the time period studied, some of the batches consisted of a mixture of phenazepam and stimulant designer drugs.The data show that phenazepam abuse is a widespread phenomenon in Finland. A typical user was a male multi-drug user in his 30. s. The concentration range of phenazepam among apprehended drivers and medico-legal autopsy cases was wide and the drug was usually found along with other psychoactive drugs. Therefore, although it seems likely that phenazepam contributed to impairment of driving in some DUID cases, the extent of its effect remains unclear and further studies are needed to define the concentrations causing impairment and toxicity. © 2012 Elsevier Ireland Ltd.


Gauriot R.,University of Helsinki | Gunaratnam L.,National Bureau of Investigation Forensic Laboratory | Moroni R.,National Bureau of Investigation Forensic Laboratory | Moroni R.,Åbo Akademi University | And 2 more authors.
Journal of Forensic Sciences | Year: 2013

The discharging of a gun results in the formation of extremely small particles known as gunshot residues (GSR). These may be deposited on the skin and clothing of the shooter, on other persons present, and on nearby items or surfaces. Several factors and their complex interactions affect the number of detectable GSR particles, which can deeply influence the conclusions drawn from likelihood ratios or posterior probabilities for prosecution hypotheses of interest. We present Bayesian network models for casework examples and demonstrate that probabilistic quantification of GSR evidence can be very sensitive to the assumptions concerning the model structure, prior probabilities, and the likelihood components. This finding has considerable implications for the use of statistical quantification of GSR evidence in the legal process. © 2013 American Academy of Forensic Sciences.


Kriikku P.,Vita Health Care Services Ltd. | Kriikku P.,University of Helsinki | Wilhelm L.,LADR GmbH MVZ Dr. Kramer and Colleagues | Rintatalo J.,National Bureau of Investigation Forensic Laboratory | And 4 more authors.
Forensic Science International | Year: 2014

Pregabalin is a medicinal drug used mainly for the treatment of epilepsy and neuropathic pain. It has been shown to possess an abuse potential and in recent years some reports of illegal use have been published. In order to further evaluate the extent and nature of pregabalin abuse, serum pregabalin levels of drivers apprehended for driving under the influence of drugs (DUID) in Finland in 2012 were assessed. The samples were analysed by an LC-MS/MS system and the results were evaluated in relation to the typical therapeutic range of pregabalin as well as the age and gender of the driver. Pregabalin was detected in 206 samples in the study period. The median (range) serum concentration was 6.2 (0.68-111.6). mg/L. In nearly 50% of the cases the serum concentration was above the typical therapeutic range. In most of the cases the driver had also taken other drugs besides pregabalin, the mean number of concomitantly taken drugs being four.Our data indicate that pregabalin is being used at high doses, probably for recreational purposes. The vast majority of the drivers positive for pregabalin in our study material had used pregabalin as a part of a spectrum of psycho-active drugs and thus qualified as probable drug abusers. In these cases pregabalin probably contributed to their driving impairment but to what extent remained unclear in this study. © 2014 Elsevier Ireland Ltd.


Kriikku P.,Vita Health Care Services Ltd. | Wilhelm L.,LADR GmbH Medizinisches Versorgungszentrum Dr. Kramer und Kollegen | Schwarz O.,LADR GmbH Medizinisches Versorgungszentrum Dr. Kramer und Kollegen | Rintatalo J.,National Bureau of Investigation Forensic Laboratory
Forensic Science International | Year: 2011

Starting in 2008 a new designer drug, 3,4-methylenedioxypyrovalerone (MDPV) appeared among users of illegal drugs in Finland. Since then there have been several seizures of MDPV by police and customs and it has been connected to many crimes of different types. In this study the incidence and impact of the use of MDPV in drivers suspected of being under the influence of drugs (DUID) in Finland was assessed.Since autumn 2009, blood samples from drivers suspected of DUID in Finland have been analysed for the presence of MDPV. A new LC-MS/MS method for the determination of MDPV in serum was established. In order to assess the impact of MDPV on driving performance, drug and alcohol findings of positive MDPV cases were compared with data from the clinical examination carried out while the suspect was under arrest. In a period of one year there were 259 positive MDPV cases from apprehended drivers (5.7% of all confirmed DUID cases). In 80% of the cases in which MDPV was found, amphetamine was also present. Benzodiazepines were also frequently found together with MDPV, which was to be expected since in Finland, in our experience, stimulants are very often used together with benzodiazepines.In most cases it remained unclear whether the observed psycho-physical achievement deficiency was induced by MDPV because the concentrations of other drugs, especially other stimulants, were often high. However, in some subjects, MDPV, or MDPV in combination with other substances was the most probable cause of the impairment. The concentrations of MDPV varied from 0.016. mg/L to over 8.000. mg/L.Little is known about the pharmacology of MDPV. However, based on our findings it is clear that MDPV has a serious impact on traffic safety in Finland. © 2011 Elsevier Ireland Ltd.


Laird A.,National Bureau of Investigation Forensic Laboratory | Lindgren K.,National Bureau of Investigation Forensic Laboratory
Journal of Forensic Identification | Year: 2011

The National Bureau of Investigation Forensic Laboratory (NBI) developed a color-coding system to simplify and standardize fingerprint analysis and comparison reports. The system has also proven useful as a training aid, because trainees are now able to more accurately demonstrate to a training officer their understanding of what they see.


PubMed | National Bureau of Investigation Forensic Laboratory
Type: Journal Article | Journal: Journal of forensic sciences | Year: 2012

A considerable amount of discussion can be found in the forensics literature about the issue of using statistical sampling to obtain for chemical analyses an appropriate subset of units from a police seizure suspected to contain illicit material. Use of the Bayesian paradigm has been suggested as the most suitable statistical approach to solving the question of how large a sample needs to be to ensure legally and practically acceptable purposes. Here, we introduce a hypergeometric sampling model combined with a specific prior distribution for the homogeneity of the seizure, where a parameter for the analysts expectation of homogeneity () is included. Our results show how an adaptive approach to sampling can minimize the practical efforts needed in the laboratory analyses, as the model allows the scientist to decide sequentially how to proceed, while maintaining a sufficiently high confidence in the conclusions.

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